Method of making heat exchange devices



July 3, 1951 J. R. HAYWARD 2,558,952

METHOD OF MAKING HEAT EXCHANGE DEVICES Filed Dec. 10, 1947 Y 2 Sheets-Sheet 1 J l6 INVENTOR. 22 JAMES R. HAYWARD ATTORAM'V July 3, 1951 J. R. HAYWARD 2,558,952

METHOD OF MAKING HEAT EXCHANGE DEVICES Filed Dec. 10, 1947 2 Sheets-Sheet 2 INVENTOR. JAMES R HAYWARD Q TTORNEY Patented July 3, 1951 METHOD OF MAKING HEAT EXCHANGE DEVICES James B. Hayward, Washington,

Ind., assignor,

by meme assignments, to MeCord Corporation,

Detroit, Mich,

a corporation of Maine Application December 10,1947, Serial No. 790,898

This invention relates to heat exchange devices such as ordinarily are used as radiators or condensers, and has particular relation to a novel method and process by which this structure may be manufactured.

Some of the objects of the invention are to provide an efiicient and inexpensive heat exchange device which may be manufactured by a relatively continuous process wherein the fin stock is formed and applied to the tubing employed in the heat exchange device before the fin stock is severed into individual fins.

Other and further objects of the invention will be apparent from the following description and claims and will be understood by reference to the accompanying drawings, of which there are two sheets, which by way of illustration show a preferred embodiment and the principles thereof and what I now consider to be thebest mode in which I have contemplated applying those principles. Other embodiments of the inventionem bodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of,

the appended claims. I also contemplate that of the several different features of my invention, certain ones thereof may be advantageously employed in some applications separate and apart from the remainder of the features.

In the drawings:

Fig. 1 is a, side elevational view of a heat exchange device embracing the principles of the invention;

Fig. 2 is an end elevational view of the structure disclosed by Fig. 1;

Fig. 3 is an enlarged fragmentary cross sectional view of the heat :.exchange device taken substantially in the plane of line 33 of Fig. 2;

Fig. 4 is a view illustrating the steps involved in the manufacture of the heat exchange device illustrated by Figs. 1 to 3;

Fig. 5 is a cross sectional view illustrating the steps in the process illustrated by Fig. 4. Fig. 5 is taken in the plane of lines 55 on Fig. 4, looking in the direction of the arrows thereon.

Referring particularly to Fig. 1, the numeral ll indicates a finned tube heat exchange device consisting principally of a tube II on which a plurality of fins I 2 is mounted. The tube H has return bends l3 formed in equally spaced relation intermediate the ends thereof to provide therebetween parallel straight sections H. The s ai ht sections ll lie in the same plane.

The fins l2 are disposed on the straight Sec- 0 Claims- (Cl. 29-1573) tions ll with'the straight sections projecting through tube openings I6 which'are formed in the fins intermediate the opposite edges thereof. About the tubeopenings l6 are formed semicircular flanges IT which project in a. plane normal to'the plane of the fin I2 and closely engage the exterior surface of the sections ll of the tube II semicircumferentially with respect thereto. The'fianges I! are formed about the openings IS in such a manner that all of the flanges project from the fin l2 on the same side of the openings I 6 with the 'ends of the flanges terminating in the plane of theaxes of the tube openings I 6. I

An illustration of a series of steps which may be employed in manufacturing the heat exchange device illustrated by Figs. 1 to 3 is illustrated in Figs. 4 and 5. In Figs. 4 and 5 a specific order and relation of steps is disclosed, although it will be apparent from Figs. 4 and 5 and the following description of the steps involved therein that the steps may be performed in different orders and that certain of the steps may be combined or eliminated al1 together.-Figs. 4 and 5, however, do represent an order of steps which may be employed in practicing the process, this order being one in which the steps are performed one at a time and successively at difler'ent work performing stations. In practicing the process disclosed in Figs. 4 and 5 there is employed a sheet of fin stock l8 which consists of a. thin sheet of metal 01' substantially planular formation. In processing this sheet of metal or fin stock It and placing the same on the straight sections I l of tube I l. the following steps may be employed.

At the first work station illustrated by the numeral 19 tube openings l6 and transverse slots 22 are simultaneously punched in the stock I 8. The tube opening I6 have major axes illustrated at 23 and minor axesillustrated at 24. Specifically,'the tube openings are formed by providing two semicircular cuts 26 and 21, the cuts 26 and 21 being concentrically disposed relative to one another with the concave edges of the cuts facing one another. The ends of the cuts 2B and- 21 are connected by radially disposed cuts 28, the cuts 26, 21 and28 being all formed at the same time and all comprising a single tube opening l6 having the major and minor axes referred to by the numerals 23 and 2| respectively. The centers 29 of all of the openings l6 lie in the same plane and extend across the fin stock l8 normal to the edges and direction of movement thereof.

The openings or transverse slots 22 also extend acrow the stool: l8 normally with respect to the edges of the stock and the direction of movement thereof. The slots 22 therefore are all equally spaced from the openings I6 and are positioned with respect to the openings I6 in such manner that the middle of each slot 22 is bisected by a line normal to the slot and projecting through the center 29 of each opening I6. Spaces 3| are provided between the adjacent ends of all of the slots 22, the spaces being preferably, although not necessarily, equal in length. The length of the transverse slots 22 is such that the ends of the slots are considerably farther apart than the lengths of the major axes 23 of the openings I6.

After the formation of the openings I6 and the transverse slots 22 is completed at work station I3, the stock is moved to work station 32 where a slit indicated at 33 is formed between a point midway between the ends of each of the transverse slots 22 and the mid portion of each semicircular cut 26. The line of severance provided by each of the slits 33, when extended, passes through the center 29 of each of the openings I6.

After the slits 33 are formed in the stock I8 the stock is moved to work station 34 where semicircular flanges are formed around one side of the openings I6 of the stock I8 which lies between the cuts 21 and semicircular lines representing extensions throughout 360 of the curvature of cuts 26. The openings I6 when so extended at work station 34 by the formation of the flanges I! are substantially equal in size and shape to the cross sectional area of the tube I. The ends of the flanges I7 formed about the openings I5 lie or terminate in the plane of the centers or axes 29 of the tube openings I6.

The stock is then moved to work station 31 where wings 38 are formed by bendin the stock I8 on lines connecting adjacent ends of the transverse slots 22 with the ends of the flanges I1. The wings 38 are bent laterally away from the plane of the stock I8 to such an extent and at such an angle that the distance between the severed edges of the stock provided by the slits 33 is substantially equal from one end to another of the tube slots 39 which are thereby formed between the wings 38. The width of the tube slots 39 is substantially equal to the diameter of each opening I6 and to' the major axis 23 of the openings I6 when such openings are initially formed.

Thereafter, at work station H the stock is severed or cut off at 42, between adjacent ends of the transverse slots 22.

Beyond the cutofi at 42 is work station 43 where the tube II is positioned with the straight sections I4 of the tube disposed normal to the plane of the stock sheet I8 and directl in front of and aligned with the tube slots 39. When the stock I8 is moved to the work station 43 it will be apparent that a fin indicated at I2 will be projected on to the tube II with the straight sections I4 of the tube passing through the slots 39 and into engagement with the flanges I'I formed about the openings I6. When the cutoff indicated at 42 is performed at work station 4| it is apparent that the fin [2 will be deposited at work station 43 in the position illustrated and described.

The width of the slots 39 and the diameters of the tube openings I6 may if desired be slightly less than the diameters of the tube sections I4 so that when the fin I2 arrives at the work station 43 and is positioned upon the tube H, the stock I8 will pinch each tube section I4 slightly so as 4 to hold each fin I2 in the position in which it is placed upon the tube II. If this is not desired, then suitable supports may be provided at work station 43 for supporting the fin I2 in any desired position.

After arriving at work station 43 the wings 33 are closed around the front of the tube sections l4 in such manner as to bring the severed edges of the slots 39 together and whereupon all of the fin stock I8 of the fin I2, except the flanges I1, will lie in the same plane. course will extend normally with respect to the plane of the fin I2 along the exterior surface of the tube sections I4. The closing of the wings 33 may be performed entirely at work station 43 or such closing of the wings 38 may commence at work station 43 and may continue during the movement of the fin I2 and tube II from work station 43 to work station 46.

Work station 46 is reached by the fin I2 by indexing the tube II in such manner as to move the tube a predetermined distance normally with respect to the plane of the fin stock and the work stations I9, 23, 34, 31, H and 43. The indexing distance referred to or the distance between work stations 43 and 46 is equal to the spacing of the fins I2 in the heat exchange device II]. Thereafter, as each new fin I2 is formed and as each fin I2 is moved from the work station 43 to the work station 46, the preceding fln I2 will be successively moved to work station 41, 43 and so on until a complete heat exchangedevice I0 is formed by placing the fins I2 upon the straight sections I4 to completely fill the space between the return bends I3. When this is done a new tube Il may be positioned to be indexed as has been previously, described throughout the successive work stations 43, 46, 41 and 48 and so on until another heat exchange device In is formed.

It will be noted from Fig. 3 that when the wings 38 are closed upon the tube sections I4, that the stock I8 of each fln I2 extends around each tube section throughout the entire circumferential extent thereof and that the flanges I'I engage the tube sections I4 semicircumferentially of the extent of the tube sections I4.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A method of making heat exchange devices which comprises forming in a sheet of fin stock, a tube opening having a major axis and a minor axis intersecting one another within said tube opening, said tube opening along said major axis being of a width approximately equal to tube width and along said minor axis being of a width substantially less than tube width, forming a transverse slot in said fin stock in spaced relation to said tube opening with the length of said transverse slot disposed in parallel relation to said major axis of said tube opening, forming a. slitbetween said tube opening and said transverse slot with the line of said slit extended bisecting said major axis and said slot, deforming said stock to provide a laterally projecting flange about said tube opening with the end extremities of said flange terminating at the extremities of said major axis of said tube opening, deforming the edges of said slit laterally between the end xtremities of the major axis of said tube opening and the adjacent end extremities of said transverse slot to form wings with the space between said wings providing a tube slot rendering said tube opening accessible from said transverse slot forming one edge of a fin by severing said fin stock between the ends of said transverse slotand the side edges of said fin stock, projecting a tube within said tube slot by relative lateral movement between said fin stock and said tube, and into said tube opening against said flange, closing said wings about said tube with the edges of said slit disposed oppositely with respect to one another and in the plane of said fin stock, and cutting said fin from said fin stock.

2. A method of making heat exchange devices which comprises forming in a sheet of fin stock, a tube opening having a major axis and a minor axis intersecting one another within said tube opening, said tube opening along said major axis being of a width approximately equal to tube width and along said minor axis being of a width substantially less than tube width, forming a transverse slot in said fin stock in spaced relation to said tube opening with the length of said transverse slot disposed in parallel relation to said major axis of said tube opening, forming a slit between said tube opening and said transverse slot with the line of said slit extended bisecting said major axis and said transverse slot, deforming said stock to provide a laterally projecting flange about said tube opening with the end extremities of said flange terminating at the extremities of said major axis of said tube opening, deforming the edges of said slit laterally between the end extremities of the major axis of said tube opening and the adjacent end extremities of said transverse slot to form wings with the space between said wings providing a tube slot rendering said tube opening accessible from said transverse slot, forming one edge of a fin by severing said fin stock between the ends of said transverse slot and the side edges of said fin stock, projecting a tube through said tube slot, by relative lateral movement between said fin stock and said tube, and into said tube opening against said flange, closing said wings about said tube with the edges of said slit disposed 0p positely with respect to one another and in the plane of said fin stock, severing said fin stock on a line parallel to said fin edge and disposed on the other side of said tube opening to form a fin, and indexing said tube longitudinally to provide space on said tube for projecting said tube into a succeeding tube slot by relative lateral movement of said fin stock and tube,

3. A method of making heat exchange devices which comprises forming in a sheet of fin stock,

a tube opening, forming a transverse slot in said fin stock in spaced relation to said tube opening, forming a slit between said tube opening and said slot, the'line of said slit extended bisecting said tube opening and said slot, deforming said stock to provide a round tube opening and a laterally extending flange about said tube opening, deforming the edges of said slit laterally between the side extremities of said tube opening and the adjacent end extremities of said slot to form wings with the space between said wings providing a tube slot rendering said tube opening accessible from said transverse slot, forming one edge of a fin by severing said fin stock between the side edges of said fin stock on a line intersecting said tube slot, projecting a tube through said tube slot by relative lateral movement between said fin stock and said tube, and into said Ill) 6 tube opening against said flange, closing said wings about said tube with the edges of said slit disposed oppositely with respect to one another and in the plane of said fin stock, cutting said fin stock at a point behind the tube assembled therein to form a fin, and indexing said tube longitudinally to provide space on said tube for projecting said tube into a succeeding tube slot by relative lateral movement of said fin stock and tube.

4. A method of making heat exchange devices which comprises forming in a sheet of fin stock, a row of tube openings, forming a row of transverse slots in said fin stock in parallel and spaced relation to said row of tube openings and'with said slots in line with said tube openings, forming a slit between each of said tube openings and a slot and with said slits parallel to each other, deforming said stock to provide a laterally extending flange about each of said openings, deforming said stock at the edges of said slits laterally between the side extremities of a tube opening and the adjacent end extremities of a slot aligned with said opening toform wings with the spaces between the wings providing tube slots rendering said tube openings accessible from said transverse slots, forming an edge of a fin by transversely cutting said stock so as to intersect said tube slots, projecting a tube transversely through each of said tube slots by relative lateral movement between said fin stock and said tube, and into said tube opening against said flange, closing said wings about said tubes with the edges of said slits disposed in the plane of said fin stock, and cutting said fin stock at a point behind the tubes assembled thereon to form a fin.

5. A method of making heat exchange devices which comprises forming in a sheet of fin stock, a tube opening having diiferent diameter relative to the length and width thereof, formin a transverse slot in said fin stock in spaced relation to said tube opening with the length of said slot disposed in parallel relation to said tube opening length, forming a slit between said tube opening and said slot, deforming said stock to provide a round tube opening and a laterally extending flange about said tube opening, deforming said stock at the edges of said slit laterally between the end extremities of said tube opening and the adjacent end extremities of said slot to form wings, the space between said wings providing a tube slot rendering said tube opening accessible from said transverse slot, forming one edge of a fin by severing said fin stock between the ends of said transverse slot and the side edges of said fin stock, projecting a round tube laterally through said tube slot by relative lateral movement between said fin stock and said tube, and into said tube opening against said flange, closing said wings about said tube with the edges of said slit disposed oppositely with respect to one another and in the plane of said fin stock, forming a second transverse slot in said fin stock on the side of said tube opening remote from said first mentioned transverse slot, and cutting said fin from said fin stock by severing said fin stock between the ends of said second transverse slot and the adjacent edges of said fin stock.

6. A method of making heat exchange devices which comprises forming in a sheet of fin stock, a tube opening, and a transverse slot in said fin stock in spaced relation longitudinally of said sheet to said tube opening, longitudinally moving said sheet of stock to a new position for a succeeding operation, forming a slit between said tube opening and said slot, longitudinally moving said sheet of stock to a new position for a succeeding operation, deforming said stock to provide a laterally extending flange about said tube opening, deforming said stock at the edges of said slit laterally between the side extremities of said tube opening and the adjacent end extremities 01! said slot to form wings With the space between said wings providing a tube slot rendering said tube opening accessible from said transverse slot, longitudinally moving said sheet of stock to a new position for a succeeding operation, forming an edge of a fin by transversely cutting said stock through said transverse slot, longitudinally moving said sheet of stock to project a tube transversely through said tube slot, and into said tube opening against said flange, closing said wings about said tube with the edges of said slit disposed oppositely with respect to one another and in the plane of said fin stock said step of cutting said stock through said transverse slot serving to sever the preceding fin from said stock, all of said operations being performed successively on one portion of said stock to form a fin and contemporaneously on different portions of said stock to partially form a series of fins at the same time.

JAMES R. HAYWARD.

France Mar. 14, 1922 

